From 1a1d23e004c7c4a3258f0a339e55a23ece46341d Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Mon, 27 Jul 2020 23:55:54 +0100
Subject: [PATCH 01/13] Unify code of `MountedApp`/`MountedCompositeView`

---
 Sources/TokamakCore/App/_AnyApp.swift         |  4 +-
 Sources/TokamakCore/App/_AnyScene.swift       |  4 +-
 .../TokamakCore/MountedViews/MountedApp.swift | 54 ++++---------------
 .../MountedCompositeElement.swift             | 14 ++---
 .../MountedViews/MountedCompositeView.swift   | 48 ++++-------------
 .../MountedViews/MountedElement.swift         |  8 +--
 Sources/TokamakCore/StackReconciler.swift     | 44 +++++++++++++++
 Sources/TokamakDOM/DOMRenderer.swift          |  6 +--
 8 files changed, 83 insertions(+), 99 deletions(-)

diff --git a/Sources/TokamakCore/App/_AnyApp.swift b/Sources/TokamakCore/App/_AnyApp.swift
index 640c9cb86..24dc7a66a 100644
--- a/Sources/TokamakCore/App/_AnyApp.swift
+++ b/Sources/TokamakCore/App/_AnyApp.swift
@@ -19,13 +19,13 @@ import OpenCombine
 
 public struct _AnyApp: App {
   var app: Any
-  let appType: Any.Type
+  let type: Any.Type
   let bodyClosure: (Any) -> _AnyScene
   let bodyType: Any.Type
 
   init<A: App>(_ app: A) {
     self.app = app
-    appType = A.self
+    type = A.self
     // swiftlint:disable:next force_cast
     bodyClosure = { _AnyScene(($0 as! A).body) }
     bodyType = A.Body.self
diff --git a/Sources/TokamakCore/App/_AnyScene.swift b/Sources/TokamakCore/App/_AnyScene.swift
index 41ad7e58d..40657c789 100644
--- a/Sources/TokamakCore/App/_AnyScene.swift
+++ b/Sources/TokamakCore/App/_AnyScene.swift
@@ -17,11 +17,11 @@
 
 public struct _AnyScene: Scene {
   let scene: Any
-  let sceneType: Any.Type
+  let type: Any.Type
 
   init<S: Scene>(_ scene: S) {
     self.scene = scene
-    sceneType = S.self
+    type = S.self
   }
 
   public var body: Never {
diff --git a/Sources/TokamakCore/MountedViews/MountedApp.swift b/Sources/TokamakCore/MountedViews/MountedApp.swift
index 0525a9c6e..314882b67 100644
--- a/Sources/TokamakCore/MountedViews/MountedApp.swift
+++ b/Sources/TokamakCore/MountedViews/MountedApp.swift
@@ -34,57 +34,25 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
     mountedChildren.forEach { $0.unmount(with: reconciler) }
   }
 
-  func mountChild<S: Scene>(_ childBody: S) -> MountedElement<R> {
+  private func mountChild<S: Scene>(_ childBody: S) -> MountedElement<R> {
     let mountedScene: MountedScene<R> = childBody.makeMountedView(parentTarget,
                                                                   environmentValues)
     if let title = mountedScene.title {
       // swiftlint:disable force_cast
-      (app.appType as! _TitledApp.Type)._setTitle(title)
+      (app.type as! _TitledApp.Type)._setTitle(title)
     }
     return mountedScene.body
   }
 
   override func update(with reconciler: StackReconciler<R>) {
-    // FIXME: for now without properly handling `Group` mounted composite views have only
-    // a single element in `mountedChildren`, but this will change when
-    // fragments are implemented and this switch should be rewritten to compare
-    // all elements in `mountedChildren`
-
-    // swiftlint:disable:next force_try
-    let appInfo = try! typeInfo(of: app.appType)
-    appInfo.injectEnvironment(from: environmentValues, into: &app.app)
-
-    switch (mountedChildren.last, reconciler.render(mountedApp: self)) {
-    // no mounted children, but children available now
-    case let (nil, childBody):
-      let child: MountedElement<R> = mountChild(childBody)
-      mountedChildren = [child]
-      child.mount(with: reconciler)
-
-    // some mounted children
-    case let (wrapper?, childBody):
-      let childBodyType = (childBody as? AnyView)?.type ?? type(of: childBody)
-
-      // FIXME: no idea if using `mangledName` is reliable, but seems to be the only way to get
-      // a name of a type constructor in runtime. Should definitely check if these are different
-      // across modules, otherwise can cause problems with views with same names in different
-      // modules.
-
-      // new child has the same type as existing child
-      // swiftlint:disable:next force_try
-      if try! wrapper.view.typeConstructorName == typeInfo(of: childBodyType).mangledName {
-        wrapper.scene = _AnyScene(childBody)
-        wrapper.update(with: reconciler)
-      } else {
-        // new child is of a different type, complete rerender, i.e. unmount the old
-        // wrapper, then mount a new one with the new `childBody`
-        wrapper.unmount(with: reconciler)
-
-        let child: MountedElement<R> = mountChild(childBody)
-        mountedChildren = [child]
-        child.mount(with: reconciler)
-      }
-    }
+    let element = reconciler.render(mountedApp: self)
+    reconciler.reconcile(
+      self,
+      with: element,
+      getElementType: { ($0 as? _AnyScene)?.type ?? type(of: $0) },
+      updateChild: { $0.scene = _AnyScene(element) },
+      mountChild: { mountChild($0) }
+    )
   }
 }
 
@@ -97,7 +65,7 @@ extension App {
     let any = (injectableApp as? _AnyApp) ?? _AnyApp(injectableApp)
     // swiftlint:disable force_try
 
-    let appInfo = try! typeInfo(of: any.appType)
+    let appInfo = try! typeInfo(of: any.type)
     var extractedApp = any.app
 
     appInfo.injectEnvironment(from: environmentValues, into: &extractedApp)
diff --git a/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift b/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
index 78bd2ec1b..22d68f46f 100644
--- a/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
@@ -34,17 +34,19 @@ class MountedCompositeElement<R: Renderer>: MountedElement<R>, Hashable {
   var subscriptions = [AnyCancellable]()
   var environmentValues: EnvironmentValues
 
-  init(_ app: _AnyApp,
-       _ parentTarget: R.TargetType,
-       _ environmentValues: EnvironmentValues) {
+  init(_ app: _AnyApp, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
     self.parentTarget = parentTarget
     self.environmentValues = environmentValues
     super.init(app)
   }
 
-  init(_ view: AnyView,
-       _ parentTarget: R.TargetType,
-       _ environmentValues: EnvironmentValues) {
+  init(_ scene: _AnyScene, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
+    self.parentTarget = parentTarget
+    self.environmentValues = environmentValues
+    super.init(scene)
+  }
+
+  init(_ view: AnyView, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
     self.parentTarget = parentTarget
     self.environmentValues = environmentValues
     super.init(view)
diff --git a/Sources/TokamakCore/MountedViews/MountedCompositeView.swift b/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
index b4c71b443..a6a2d25d7 100644
--- a/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
+++ b/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
@@ -26,8 +26,7 @@ final class MountedCompositeView<R: Renderer>: MountedCompositeElement<R> {
       appearanceAction.appear?()
     }
 
-    let child: MountedElement<R> = childBody.makeMountedView(parentTarget,
-                                                             environmentValues)
+    let child: MountedElement<R> = childBody.makeMountedView(parentTarget, environmentValues)
     mountedChildren = [child]
     child.mount(with: reconciler)
   }
@@ -41,42 +40,13 @@ final class MountedCompositeView<R: Renderer>: MountedCompositeElement<R> {
   }
 
   override func update(with reconciler: StackReconciler<R>) {
-    // FIXME: for now without properly handling `Group` mounted composite views have only
-    // a single element in `mountedChildren`, but this will change when
-    // fragments are implemented and this switch should be rewritten to compare
-    // all elements in `mountedChildren`
-    switch (mountedChildren.last, reconciler.render(compositeView: self)) {
-    // no mounted children, but children available now
-    case let (nil, childBody):
-      let child: MountedElement<R> = childBody.makeMountedView(parentTarget,
-                                                               environmentValues)
-      mountedChildren = [child]
-      child.mount(with: reconciler)
-
-    // some mounted children
-    case let (wrapper?, childBody):
-      let childBodyType = (childBody as? AnyView)?.type ?? type(of: childBody)
-
-      // FIXME: no idea if using `mangledName` is reliable, but seems to be the only way to get
-      // a name of a type constructor in runtime. Should definitely check if these are different
-      // across modules, otherwise can cause problems with views with same names in different
-      // modules.
-
-      // new child has the same type as existing child
-      // swiftlint:disable:next force_try
-      if try! wrapper.view.typeConstructorName == typeInfo(of: childBodyType).mangledName {
-        wrapper.view = AnyView(childBody)
-        wrapper.update(with: reconciler)
-      } else {
-        // new child is of a different type, complete rerender, i.e. unmount the old
-        // wrapper, then mount a new one with the new `childBody`
-        wrapper.unmount(with: reconciler)
-
-        let child: MountedElement<R> = childBody.makeMountedView(parentTarget,
-                                                                 environmentValues)
-        mountedChildren = [child]
-        child.mount(with: reconciler)
-      }
-    }
+    let element = reconciler.render(compositeView: self)
+    reconciler.reconcile(
+      self,
+      with: element,
+      getElementType: { ($0 as? AnyView)?.type ?? type(of: $0) },
+      updateChild: { $0.view = AnyView(element) },
+      mountChild: { $0.makeMountedView(parentTarget, environmentValues) }
+    )
   }
 }
diff --git a/Sources/TokamakCore/MountedViews/MountedElement.swift b/Sources/TokamakCore/MountedViews/MountedElement.swift
index 6ef1d8819..167af4710 100644
--- a/Sources/TokamakCore/MountedViews/MountedElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedElement.swift
@@ -25,7 +25,7 @@ enum MountedElementKind {
 }
 
 public class MountedElement<R: Renderer> {
-  var element: MountedElementKind
+  private var element: MountedElementKind
 
   public internal(set) var app: _AnyApp {
     get {
@@ -67,8 +67,8 @@ public class MountedElement<R: Renderer> {
 
   var elementType: Any.Type {
     switch element {
-    case let .app(app): return app.appType
-    case let .scene(scene): return scene.sceneType
+    case let .app(app): return app.type
+    case let .scene(scene): return scene.type
     case let .view(view): return view.type
     }
   }
@@ -188,7 +188,7 @@ extension Scene {
     } else if let groupSelf = anySelf.scene as? GroupScene {
       return groupSelf.children[0].makeMountedView(parentTarget, environmentValues)
     } else {
-      fatalError("Unsupported `Scene` type `\(anySelf.sceneType)`. Please file a bug report.")
+      fatalError("Unsupported `Scene` type `\(anySelf.type)`. Please file a bug report.")
     }
   }
 }
diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index 51b022d32..d4f2d0e89 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -171,4 +171,48 @@ public final class StackReconciler<R: Renderer> {
   func render(mountedApp: MountedApp<R>) -> some Scene {
     render(compositeElement: mountedApp, body: \.app.app, result: \.app.bodyClosure)
   }
+
+  func reconcile<E>(
+    _ mountedElement: MountedCompositeElement<R>,
+    with element: E,
+    getElementType: (E) -> Any.Type,
+    updateChild: (MountedElement<R>) -> (),
+    mountChild: (E) -> MountedElement<R>
+  ) {
+    // FIXME: for now without properly handling `Group` and `TupleView` mounted composite views
+    // have only a single element in `mountedChildren`, but this will change when
+    // fragments are implemented and this switch should be rewritten to compare
+    // all elements in `mountedChildren`
+    switch (mountedElement.mountedChildren.last, element) {
+    // no mounted children previously, but children available now
+    case let (nil, childBody):
+      let child: MountedElement<R> = mountChild(childBody)
+      mountedElement.mountedChildren = [child]
+      child.mount(with: self)
+
+    // some mounted children before and now
+    case let (mountedChild?, childBody):
+      let childBodyType = getElementType(childBody)
+
+      // FIXME: no idea if using `mangledName` is reliable, but seems to be the only way to get
+      // a name of a type constructor in runtime. Should definitely check if these are different
+      // across modules, otherwise can cause problems with views with same names in different
+      // modules.
+
+      // new child has the same type as existing child
+      // swiftlint:disable:next force_try
+      if try! mountedChild.view.typeConstructorName == typeInfo(of: childBodyType).mangledName {
+        updateChild(mountedChild)
+        mountedChild.update(with: self)
+      } else {
+        // new child is of a different type, complete rerender, i.e. unmount the old
+        // wrapper, then mount a new one with the new `childBody`
+        mountedChild.unmount(with: self)
+
+        let newMountedChild: MountedElement<R> = mountChild(childBody)
+        mountedElement.mountedChildren = [newMountedChild]
+        newMountedChild.mount(with: self)
+      }
+    }
+  }
 }
diff --git a/Sources/TokamakDOM/DOMRenderer.swift b/Sources/TokamakDOM/DOMRenderer.swift
index 31a33ae12..e9f5ffe9c 100644
--- a/Sources/TokamakDOM/DOMRenderer.swift
+++ b/Sources/TokamakDOM/DOMRenderer.swift
@@ -30,10 +30,10 @@ extension EnvironmentValues {
   }
 }
 
-/** `SpacerContainer` is part of TokamakDOM, as not all renderers will handle flexible 
- sizing the way browsers do. Their parent element could already know that if a child is 
+/** `SpacerContainer` is part of TokamakDOM, as not all renderers will handle flexible
+ sizing the way browsers do. Their parent element could already know that if a child is
  requesting full width, then it needs to expand.
-*/
+ */
 private extension AnyView {
   var axes: [SpacerContainerAxis] {
     var axes = [SpacerContainerAxis]()

From 4ad8859a80c8d55a3e4780de1854b9359c87fac3 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Tue, 28 Jul 2020 00:02:05 +0100
Subject: [PATCH 02/13] Make generic type name more verbose

---
 Sources/TokamakCore/StackReconciler.swift | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index d4f2d0e89..cd65fd3fc 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -172,12 +172,12 @@ public final class StackReconciler<R: Renderer> {
     render(compositeElement: mountedApp, body: \.app.app, result: \.app.bodyClosure)
   }
 
-  func reconcile<E>(
+  func reconcile<Element>(
     _ mountedElement: MountedCompositeElement<R>,
-    with element: E,
-    getElementType: (E) -> Any.Type,
+    with element: Element,
+    getElementType: (Element) -> Any.Type,
     updateChild: (MountedElement<R>) -> (),
-    mountChild: (E) -> MountedElement<R>
+    mountChild: (Element) -> MountedElement<R>
   ) {
     // FIXME: for now without properly handling `Group` and `TupleView` mounted composite views
     // have only a single element in `mountedChildren`, but this will change when

From 42e68cb72daa879199cbd80c9c0d77192eec4d43 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Tue, 28 Jul 2020 00:36:36 +0100
Subject: [PATCH 03/13] MountedScene work in progress

---
 Sources/TokamakCore/App/_AnyScene.swift       |  5 ++
 .../TokamakCore/MountedViews/MountedApp.swift |  3 +-
 .../MountedViews/MountedElement.swift         | 25 ------
 .../MountedViews/MountedScene.swift           | 81 +++++++++++++++++++
 Sources/TokamakCore/StackReconciler.swift     |  4 +
 5 files changed, 91 insertions(+), 27 deletions(-)
 create mode 100644 Sources/TokamakCore/MountedViews/MountedScene.swift

diff --git a/Sources/TokamakCore/App/_AnyScene.swift b/Sources/TokamakCore/App/_AnyScene.swift
index 40657c789..ec0bc3bd2 100644
--- a/Sources/TokamakCore/App/_AnyScene.swift
+++ b/Sources/TokamakCore/App/_AnyScene.swift
@@ -18,10 +18,15 @@
 public struct _AnyScene: Scene {
   let scene: Any
   let type: Any.Type
+  let bodyClosure: (Any) -> _AnyScene
+  let bodyType: Any.Type
 
   init<S: Scene>(_ scene: S) {
     self.scene = scene
     type = S.self
+    // swiftlint:disable:next force_cast
+    bodyClosure = { _AnyScene(($0 as! S).body) }
+    bodyType = S.Body.self
   }
 
   public var body: Never {
diff --git a/Sources/TokamakCore/MountedViews/MountedApp.swift b/Sources/TokamakCore/MountedViews/MountedApp.swift
index 314882b67..5210adcd5 100644
--- a/Sources/TokamakCore/MountedViews/MountedApp.swift
+++ b/Sources/TokamakCore/MountedViews/MountedApp.swift
@@ -35,8 +35,7 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
   }
 
   private func mountChild<S: Scene>(_ childBody: S) -> MountedElement<R> {
-    let mountedScene: MountedScene<R> = childBody.makeMountedView(parentTarget,
-                                                                  environmentValues)
+    let mountedScene: MountedScene<R> = childBody.makeMountedScene(parentTarget, environmentValues)
     if let title = mountedScene.title {
       // swiftlint:disable force_cast
       (app.type as! _TitledApp.Type)._setTitle(title)
diff --git a/Sources/TokamakCore/MountedViews/MountedElement.swift b/Sources/TokamakCore/MountedViews/MountedElement.swift
index 167af4710..dee03382b 100644
--- a/Sources/TokamakCore/MountedViews/MountedElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedElement.swift
@@ -167,28 +167,3 @@ extension View {
     }
   }
 }
-
-typealias MountedScene<R: Renderer> = (body: MountedElement<R>, title: String?)
-
-extension Scene {
-  func makeMountedView<R: Renderer>(
-    _ parentTarget: R.TargetType,
-    _ environmentValues: EnvironmentValues
-  ) -> MountedScene<R> {
-    let anySelf = (self as? _AnyScene) ?? _AnyScene(self)
-    var title: String?
-    if let titledSelf = anySelf.scene as? TitledScene,
-      let text = titledSelf.title {
-      title = _TextProxy(text).rawText
-    }
-    if let viewSelf = anySelf.scene as? ViewContainingScene {
-      return (body: viewSelf.anyContent.makeMountedView(parentTarget, environmentValues), title)
-    } else if let deferredSelf = anySelf.scene as? SceneDeferredToRenderer {
-      return (deferredSelf.deferredBody.makeMountedView(parentTarget, environmentValues), title)
-    } else if let groupSelf = anySelf.scene as? GroupScene {
-      return groupSelf.children[0].makeMountedView(parentTarget, environmentValues)
-    } else {
-      fatalError("Unsupported `Scene` type `\(anySelf.type)`. Please file a bug report.")
-    }
-  }
-}
diff --git a/Sources/TokamakCore/MountedViews/MountedScene.swift b/Sources/TokamakCore/MountedViews/MountedScene.swift
new file mode 100644
index 000000000..c0d0134fc
--- /dev/null
+++ b/Sources/TokamakCore/MountedViews/MountedScene.swift
@@ -0,0 +1,81 @@
+// Copyright 2020 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+final class MountedScene<R: Renderer>: MountedCompositeElement<R> {
+  let title: String?
+
+  init(
+    _ scene: _AnyScene,
+    _ title: String?,
+    _ children: [MountedElement<R>],
+    _ parentTarget: R.TargetType,
+    _ environmentValues: EnvironmentValues
+  ) {
+    self.title = title
+    super.init(scene, parentTarget, environmentValues)
+    mountedChildren = children
+  }
+
+  override func mount(with reconciler: StackReconciler<R>) {
+    let childBody = reconciler.render(mountedScene: self)
+
+    let child: MountedElement<R> = childBody.makeMountedScene(parentTarget, environmentValues)
+    mountedChildren = [child]
+    child.mount(with: reconciler)
+  }
+
+  override func unmount(with reconciler: StackReconciler<R>) {
+    mountedChildren.forEach { $0.unmount(with: reconciler) }
+  }
+
+  override func update(with reconciler: StackReconciler<R>) {
+    let element = reconciler.render(mountedScene: self)
+    reconciler.reconcile(
+      self,
+      with: element,
+      getElementType: { ($0 as? _AnyScene)?.type ?? type(of: $0) },
+      updateChild: { $0.scene = _AnyScene(element) },
+      mountChild: { $0.makeMountedScene(parentTarget, environmentValues) }
+    )
+  }
+}
+
+extension Scene {
+  func makeMountedScene<R: Renderer>(
+    _ parentTarget: R.TargetType,
+    _ environmentValues: EnvironmentValues
+  ) -> MountedScene<R> {
+    let anySelf = (self as? _AnyScene) ?? _AnyScene(self)
+    var title: String?
+    if let titledSelf = anySelf.scene as? TitledScene,
+      let text = titledSelf.title {
+      title = _TextProxy(text).rawText
+    }
+    let children: [MountedElement<R>]
+    if let viewSelf = anySelf.scene as? ViewContainingScene {
+      children = [viewSelf.anyContent.makeMountedView(parentTarget, environmentValues)]
+    } else if let deferredSelf = anySelf.scene as? SceneDeferredToRenderer {
+      children = [deferredSelf.deferredBody.makeMountedView(parentTarget, environmentValues)]
+    } else if let groupSelf = anySelf.scene as? GroupScene {
+      children = groupSelf.children.map { $0.makeMountedScene(parentTarget, environmentValues) }
+    } else {
+      fatalError("""
+      Unsupported `Scene` type `\(anySelf.type)`. Please file a bug report at \
+      https://github.com/swiftwasm/Tokamak/issues/new
+      """)
+    }
+
+    return .init(anySelf, title, children, parentTarget, environmentValues)
+  }
+}
diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index cd65fd3fc..5818ea6a4 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -172,6 +172,10 @@ public final class StackReconciler<R: Renderer> {
     render(compositeElement: mountedApp, body: \.app.app, result: \.app.bodyClosure)
   }
 
+  func render(mountedScene: MountedScene<R>) -> some Scene {
+    render(compositeElement: mountedScene, body: \.scene.scene, result: \.scene.bodyClosure)
+  }
+
   func reconcile<Element>(
     _ mountedElement: MountedCompositeElement<R>,
     with element: Element,

From 190f1657ede6aa98fa6a95b101f7ef6efb2cc61c Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Tue, 28 Jul 2020 15:30:00 +0100
Subject: [PATCH 04/13] Fix build issues

---
 Sources/TokamakCore/App/_AnyScene.swift           | 2 +-
 Sources/TokamakCore/MountedViews/MountedApp.swift | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sources/TokamakCore/App/_AnyScene.swift b/Sources/TokamakCore/App/_AnyScene.swift
index ec0bc3bd2..dad77adfc 100644
--- a/Sources/TokamakCore/App/_AnyScene.swift
+++ b/Sources/TokamakCore/App/_AnyScene.swift
@@ -16,7 +16,7 @@
 //
 
 public struct _AnyScene: Scene {
-  let scene: Any
+  var scene: Any
   let type: Any.Type
   let bodyClosure: (Any) -> _AnyScene
   let bodyType: Any.Type
diff --git a/Sources/TokamakCore/MountedViews/MountedApp.swift b/Sources/TokamakCore/MountedViews/MountedApp.swift
index 5210adcd5..49bfcad56 100644
--- a/Sources/TokamakCore/MountedViews/MountedApp.swift
+++ b/Sources/TokamakCore/MountedViews/MountedApp.swift
@@ -40,7 +40,7 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
       // swiftlint:disable force_cast
       (app.type as! _TitledApp.Type)._setTitle(title)
     }
-    return mountedScene.body
+    return mountedScene
   }
 
   override func update(with reconciler: StackReconciler<R>) {

From 2099d902dc86d2a0b843f568a66b919dfda81f80 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 10:45:52 +0100
Subject: [PATCH 05/13] Refine _AnyScene code and AnyView docs

---
 Sources/TokamakCore/App/_AnyScene.swift | 18 +++++++++++++++---
 Sources/TokamakCore/Views/AnyView.swift | 18 ++++++++++++++++--
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/Sources/TokamakCore/App/_AnyScene.swift b/Sources/TokamakCore/App/_AnyScene.swift
index dad77adfc..fa54cf4fb 100644
--- a/Sources/TokamakCore/App/_AnyScene.swift
+++ b/Sources/TokamakCore/App/_AnyScene.swift
@@ -16,17 +16,29 @@
 //
 
 public struct _AnyScene: Scene {
+  enum BodyResult {
+    case scene(_AnyScene)
+    case view(AnyView)
+  }
+
   var scene: Any
+
+  /// The type of the underlying `scene`
   let type: Any.Type
-  let bodyClosure: (Any) -> _AnyScene
+  let bodyClosure: (Any) -> BodyResult
   let bodyType: Any.Type
 
   init<S: Scene>(_ scene: S) {
     self.scene = scene
     type = S.self
-    // swiftlint:disable:next force_cast
-    bodyClosure = { _AnyScene(($0 as! S).body) }
     bodyType = S.Body.self
+    if scene is SceneDeferredToRenderer {
+      // swiftlint:disable:next force_cast
+      bodyClosure = { .view(($0 as! SceneDeferredToRenderer).deferredBody) }
+    } else {
+      // swiftlint:disable:next force_cast
+      bodyClosure = { .scene(_AnyScene(($0 as! S).body)) }
+    }
   }
 
   public var body: Never {
diff --git a/Sources/TokamakCore/Views/AnyView.swift b/Sources/TokamakCore/Views/AnyView.swift
index f009f929c..8f9995b32 100644
--- a/Sources/TokamakCore/Views/AnyView.swift
+++ b/Sources/TokamakCore/Views/AnyView.swift
@@ -19,13 +19,27 @@ import Runtime
 
 /// A type-erased view.
 public struct AnyView: View {
+  /// The type of the underlying `view`.
   let type: Any.Type
+
+  /** The name of the unapplied generic type of the underlying view. `Button<Text>` and
+   `Button<Image>` types are different, but when reconciling the tree of mounted views
+   they are treated the same, thus the `Button` part of the type (the type constructor)
+   is stored in this property.
+   */
   let typeConstructorName: String
+
+  /** The type of the `body` of the underlying `view`. Used to cast the result of the applied
+   `bodyClosure` property.
+   */
   let bodyType: Any.Type
+
+  /// The actual `View` value wrapped within this `AnyView`.
   var view: Any
 
-  // needs to take a fresh version of `view` as an argument,
-  // otherwise it captures the old view value
+  /** Type-erased `body` of the underlying `view`. Needs to take a fresh version of `view` as an
+   argument, otherwise it captures the old view value.
+   */
   let bodyClosure: (Any) -> AnyView
 
   public init<V>(_ view: V) where V: View {

From 74e935569a825e0c35c8c64e8a45224c485205a6 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 16:17:52 +0100
Subject: [PATCH 06/13] Fix scenes, improve documentation

---
 Sources/TokamakCore/App/Scenes/Scene.swift    |  4 --
 .../TokamakCore/App/Scenes/WindowGroup.swift  |  2 +-
 Sources/TokamakCore/App/_AnyScene.swift       | 48 ++++++++++++++---
 .../TokamakCore/MountedViews/MountedApp.swift |  4 +-
 .../MountedViews/MountedCompositeView.swift   |  2 +-
 .../MountedViews/MountedElement.swift         | 12 +++++
 .../MountedViews/MountedScene.swift           | 53 ++++++++++++++-----
 Sources/TokamakCore/StackReconciler.swift     | 45 ++++++++++++++--
 Sources/TokamakCore/Views/AnyView.swift       | 20 +++----
 9 files changed, 145 insertions(+), 45 deletions(-)

diff --git a/Sources/TokamakCore/App/Scenes/Scene.swift b/Sources/TokamakCore/App/Scenes/Scene.swift
index 01e84d248..585fc30c4 100644
--- a/Sources/TokamakCore/App/Scenes/Scene.swift
+++ b/Sources/TokamakCore/App/Scenes/Scene.swift
@@ -27,10 +27,6 @@ protocol TitledScene {
   var title: Text? { get }
 }
 
-protocol ViewContainingScene {
-  var anyContent: AnyView { get }
-}
-
 protocol ParentScene {
   var children: [_AnyScene] { get }
 }
diff --git a/Sources/TokamakCore/App/Scenes/WindowGroup.swift b/Sources/TokamakCore/App/Scenes/WindowGroup.swift
index e36ebd678..04c325d26 100644
--- a/Sources/TokamakCore/App/Scenes/WindowGroup.swift
+++ b/Sources/TokamakCore/App/Scenes/WindowGroup.swift
@@ -15,7 +15,7 @@
 //  Created by Carson Katri on 7/16/20.
 //
 
-public struct WindowGroup<Content>: Scene, TitledScene, ViewContainingScene where Content: View {
+public struct WindowGroup<Content>: Scene, TitledScene where Content: View {
   public let id: String
   public let title: Text?
   public let content: Content
diff --git a/Sources/TokamakCore/App/_AnyScene.swift b/Sources/TokamakCore/App/_AnyScene.swift
index fa54cf4fb..f5bbb5793 100644
--- a/Sources/TokamakCore/App/_AnyScene.swift
+++ b/Sources/TokamakCore/App/_AnyScene.swift
@@ -15,29 +15,61 @@
 //  Created by Carson Katri on 7/19/20.
 //
 
+import Runtime
+
 public struct _AnyScene: Scene {
+  /** The result type of `bodyClosure` allowing to disambiguate between scenes that
+   produce other scenes or scenes that only produce containing views.
+   */
   enum BodyResult {
     case scene(_AnyScene)
     case view(AnyView)
   }
 
+  /** The name of the unapplied generic type of the underlying `view`. `Button<Text>` and
+   `Button<Image>` types are different, but when reconciling the tree of mounted views
+   they are treated the same, thus the `Button` part of the type (the type constructor)
+   is stored in this property.
+   */
+  let typeConstructorName: String
+
+  /// The actual `Scene` value wrapped within this `_AnyScene`.
   var scene: Any
 
   /// The type of the underlying `scene`
   let type: Any.Type
+
+  /** Type-erased `body` of the underlying `scene`. Needs to take a fresh version of `scene` as an
+   argument, otherwise it captures an old value of the `body` property.
+   */
   let bodyClosure: (Any) -> BodyResult
+
+  /** The type of the `body` of the underlying `scene`. Used to cast the result of the applied
+   `bodyClosure` property.
+   */
   let bodyType: Any.Type
 
   init<S: Scene>(_ scene: S) {
-    self.scene = scene
-    type = S.self
-    bodyType = S.Body.self
-    if scene is SceneDeferredToRenderer {
-      // swiftlint:disable:next force_cast
-      bodyClosure = { .view(($0 as! SceneDeferredToRenderer).deferredBody) }
+    if let anyScene = scene as? _AnyScene {
+      self = anyScene
     } else {
-      // swiftlint:disable:next force_cast
-      bodyClosure = { .scene(_AnyScene(($0 as! S).body)) }
+      self.scene = scene
+      type = S.self
+      bodyType = S.Body.self
+      if scene is SceneDeferredToRenderer {
+        // swiftlint:disable:next force_cast
+        bodyClosure = { .view(($0 as! SceneDeferredToRenderer).deferredBody) }
+      } else {
+        // swiftlint:disable:next force_cast
+        bodyClosure = { .scene(_AnyScene(($0 as! S).body)) }
+      }
+      // FIXME: no idea if using `mangledName` is reliable, but seems to be the only way to get
+      // a name of a type constructor in runtime. Should definitely check if these are different
+      // across modules, otherwise can cause problems with scenes with same names in different
+      // modules.
+
+      // swiftlint:disable:next force_try
+      typeConstructorName = try! typeInfo(of: type).mangledName
     }
   }
 
diff --git a/Sources/TokamakCore/MountedViews/MountedApp.swift b/Sources/TokamakCore/MountedViews/MountedApp.swift
index 49bfcad56..b77d14056 100644
--- a/Sources/TokamakCore/MountedViews/MountedApp.swift
+++ b/Sources/TokamakCore/MountedViews/MountedApp.swift
@@ -34,7 +34,7 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
     mountedChildren.forEach { $0.unmount(with: reconciler) }
   }
 
-  private func mountChild<S: Scene>(_ childBody: S) -> MountedElement<R> {
+  private func mountChild(_ childBody: _AnyScene) -> MountedElement<R> {
     let mountedScene: MountedScene<R> = childBody.makeMountedScene(parentTarget, environmentValues)
     if let title = mountedScene.title {
       // swiftlint:disable force_cast
@@ -48,7 +48,7 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
     reconciler.reconcile(
       self,
       with: element,
-      getElementType: { ($0 as? _AnyScene)?.type ?? type(of: $0) },
+      getElementType: { $0.type },
       updateChild: { $0.scene = _AnyScene(element) },
       mountChild: { mountChild($0) }
     )
diff --git a/Sources/TokamakCore/MountedViews/MountedCompositeView.swift b/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
index a6a2d25d7..d477097a1 100644
--- a/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
+++ b/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
@@ -44,7 +44,7 @@ final class MountedCompositeView<R: Renderer>: MountedCompositeElement<R> {
     reconciler.reconcile(
       self,
       with: element,
-      getElementType: { ($0 as? AnyView)?.type ?? type(of: $0) },
+      getElementType: { $0.type },
       updateChild: { $0.view = AnyView(element) },
       mountChild: { $0.makeMountedView(parentTarget, environmentValues) }
     )
diff --git a/Sources/TokamakCore/MountedViews/MountedElement.swift b/Sources/TokamakCore/MountedViews/MountedElement.swift
index dee03382b..8910af708 100644
--- a/Sources/TokamakCore/MountedViews/MountedElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedElement.swift
@@ -73,6 +73,18 @@ public class MountedElement<R: Renderer> {
     }
   }
 
+  var typeConstructorName: String {
+    switch element {
+    case .app: fatalError("""
+    `App` values aren't supposed to be reconciled, thus the type constructor name is not stored \
+    for `App` elements. Please report this crash as a bug at \
+    https://github.com/swiftwasm/Tokamak/issues/new
+    """)
+    case let .scene(scene): return scene.typeConstructorName
+    case let .view(view): return view.typeConstructorName
+    }
+  }
+
   init(_ app: _AnyApp) {
     element = .app(app)
   }
diff --git a/Sources/TokamakCore/MountedViews/MountedScene.swift b/Sources/TokamakCore/MountedViews/MountedScene.swift
index c0d0134fc..d91e93205 100644
--- a/Sources/TokamakCore/MountedViews/MountedScene.swift
+++ b/Sources/TokamakCore/MountedViews/MountedScene.swift
@@ -30,7 +30,7 @@ final class MountedScene<R: Renderer>: MountedCompositeElement<R> {
   override func mount(with reconciler: StackReconciler<R>) {
     let childBody = reconciler.render(mountedScene: self)
 
-    let child: MountedElement<R> = childBody.makeMountedScene(parentTarget, environmentValues)
+    let child: MountedElement<R> = childBody.makeMountedElement(parentTarget, environmentValues)
     mountedChildren = [child]
     child.mount(with: reconciler)
   }
@@ -44,38 +44,65 @@ final class MountedScene<R: Renderer>: MountedCompositeElement<R> {
     reconciler.reconcile(
       self,
       with: element,
-      getElementType: { ($0 as? _AnyScene)?.type ?? type(of: $0) },
-      updateChild: { $0.scene = _AnyScene(element) },
-      mountChild: { $0.makeMountedScene(parentTarget, environmentValues) }
+      getElementType: { $0.type },
+      updateChild: {
+        switch element {
+        case let .scene(scene):
+          $0.scene = _AnyScene(scene)
+        case let .view(view):
+          $0.view = AnyView(view)
+        }
+      },
+      mountChild: { $0.makeMountedElement(parentTarget, environmentValues) }
     )
   }
 }
 
-extension Scene {
+extension _AnyScene.BodyResult {
+  var type: Any.Type {
+    switch self {
+    case let .scene(scene):
+      return scene.type
+    case let .view(view):
+      return view.type
+    }
+  }
+
+  func makeMountedElement<R: Renderer>(
+    _ parentTarget: R.TargetType,
+    _ environmentValues: EnvironmentValues
+  ) -> MountedElement<R> {
+    switch self {
+    case let .scene(scene):
+      return scene.makeMountedScene(parentTarget, environmentValues)
+    case let .view(view):
+      return view.makeMountedView(parentTarget, environmentValues)
+    }
+  }
+}
+
+extension _AnyScene {
   func makeMountedScene<R: Renderer>(
     _ parentTarget: R.TargetType,
     _ environmentValues: EnvironmentValues
   ) -> MountedScene<R> {
-    let anySelf = (self as? _AnyScene) ?? _AnyScene(self)
     var title: String?
-    if let titledSelf = anySelf.scene as? TitledScene,
+    if let titledSelf = scene as? TitledScene,
       let text = titledSelf.title {
       title = _TextProxy(text).rawText
     }
     let children: [MountedElement<R>]
-    if let viewSelf = anySelf.scene as? ViewContainingScene {
-      children = [viewSelf.anyContent.makeMountedView(parentTarget, environmentValues)]
-    } else if let deferredSelf = anySelf.scene as? SceneDeferredToRenderer {
+    if let deferredSelf = scene as? SceneDeferredToRenderer {
       children = [deferredSelf.deferredBody.makeMountedView(parentTarget, environmentValues)]
-    } else if let groupSelf = anySelf.scene as? GroupScene {
+    } else if let groupSelf = scene as? GroupScene {
       children = groupSelf.children.map { $0.makeMountedScene(parentTarget, environmentValues) }
     } else {
       fatalError("""
-      Unsupported `Scene` type `\(anySelf.type)`. Please file a bug report at \
+      Unsupported `Scene` type `\(type)`. Please file a bug report at \
       https://github.com/swiftwasm/Tokamak/issues/new
       """)
     }
 
-    return .init(anySelf, title, children, parentTarget, environmentValues)
+    return .init(self, title, children, parentTarget, environmentValues)
   }
 }
diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index 5818ea6a4..0db5e7f67 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -18,12 +18,49 @@
 import OpenCombine
 import Runtime
 
+/** A class that reconciles a "raw" tree of element values (such as `App`, `Scene` and `View`,
+ all coming from `body` or `deferredBody` properties) with a tree of mounted element instances
+ ('MountedApp', `MountedScene`, `MountedCompositeView` and `MountedHostView` respectively). Any
+ updates to the former tree are reflected in the latter tree, and then resulting changes are
+ delegated to the renderer for it to reflect those in its viewport.
+
+ Scheduled updates are stored in a simple stack-like structure and are processed sequentially as
+ opposed to potentially more sophisticated implementations. [React's fiber
+ reconciler](https://github.com/acdlite/react-fiber-architecture) is one of those and could be
+ implemented in the future to improve UI responsiveness under heavy load and potentially even
+ support multi-threading when it's supported in WebAssembly.
+ */
 public final class StackReconciler<R: Renderer> {
+  /** A set of mounted elements that triggered a re-render. These are stored in a `Set` instead of
+   an array to avoid duplicate re-renders. The actual performance benefits of such de-duplication
+   haven't been proven in the absence of benchmarks, so this could be updated to a simple `Array` in
+   the future if that's proven to be more effective.
+   */
   private var queuedRerenders = Set<MountedCompositeElement<R>>()
 
+  /** A root renderer's target instance. We establish the "host-target" terminology where a "host"
+   is a primitive `View` that doesn't have any children, and a "target" is an instance of a type
+   declared by a rendererto which the "host" is rendered to. For example, in the DOM renderer a
+   "target" is a DOM node, in a hypothetical iOS renderer it would be a `UIView`, and a macOS
+   renderer would declare an `NSView` as its "target" type.
+   */
   public let rootTarget: R.TargetType
+
+  /** A root of the mounted elements tree to which all other mounted elements are attached to.
+   */
   private let rootElement: MountedElement<R>
+
+  /** A renderer instances to delegate to. Usually the renderer owns the reconciler instance, thus
+   the reference has to be weak to avoid a reference cycle.
+   **/
   private(set) weak var renderer: R?
+
+  /** A platform-specific implementation of an event loop cycle scheduler. Usually reconciler
+   updates are scheduled in reponse to user input. To make the updates non-blocking so that app
+   feels responsive, the actual reconcilliation needs to be scheduled on the next event loop cycle.
+   Usually it's `DispatchQueue.main.async` on platforms where `Dispatch` is supported, or
+   `setTimeout` in the DOM environment.
+   */
   private let scheduler: (@escaping () -> ()) -> ()
 
   public init<V: View>(
@@ -164,15 +201,15 @@ public final class StackReconciler<R: Renderer> {
     return compositeElement[keyPath: result](compositeElement[keyPath: bodyKeypath])
   }
 
-  func render(compositeView: MountedCompositeView<R>) -> some View {
+  func render(compositeView: MountedCompositeView<R>) -> AnyView {
     render(compositeElement: compositeView, body: \.view.view, result: \.view.bodyClosure)
   }
 
-  func render(mountedApp: MountedApp<R>) -> some Scene {
+  func render(mountedApp: MountedApp<R>) -> _AnyScene {
     render(compositeElement: mountedApp, body: \.app.app, result: \.app.bodyClosure)
   }
 
-  func render(mountedScene: MountedScene<R>) -> some Scene {
+  func render(mountedScene: MountedScene<R>) -> _AnyScene.BodyResult {
     render(compositeElement: mountedScene, body: \.scene.scene, result: \.scene.bodyClosure)
   }
 
@@ -205,7 +242,7 @@ public final class StackReconciler<R: Renderer> {
 
       // new child has the same type as existing child
       // swiftlint:disable:next force_try
-      if try! mountedChild.view.typeConstructorName == typeInfo(of: childBodyType).mangledName {
+      if try! mountedChild.typeConstructorName == typeInfo(of: childBodyType).mangledName {
         updateChild(mountedChild)
         mountedChild.update(with: self)
       } else {
diff --git a/Sources/TokamakCore/Views/AnyView.swift b/Sources/TokamakCore/Views/AnyView.swift
index 8f9995b32..95d59a224 100644
--- a/Sources/TokamakCore/Views/AnyView.swift
+++ b/Sources/TokamakCore/Views/AnyView.swift
@@ -22,33 +22,29 @@ public struct AnyView: View {
   /// The type of the underlying `view`.
   let type: Any.Type
 
-  /** The name of the unapplied generic type of the underlying view. `Button<Text>` and
+  /** The name of the unapplied generic type of the underlying `view`. `Button<Text>` and
    `Button<Image>` types are different, but when reconciling the tree of mounted views
    they are treated the same, thus the `Button` part of the type (the type constructor)
    is stored in this property.
    */
   let typeConstructorName: String
 
-  /** The type of the `body` of the underlying `view`. Used to cast the result of the applied
-   `bodyClosure` property.
-   */
-  let bodyType: Any.Type
-
   /// The actual `View` value wrapped within this `AnyView`.
   var view: Any
 
   /** Type-erased `body` of the underlying `view`. Needs to take a fresh version of `view` as an
-   argument, otherwise it captures the old view value.
+   argument, otherwise it captures an old value of the `body` property.
    */
   let bodyClosure: (Any) -> AnyView
 
+  /** The type of the `body` of the underlying `view`. Used to cast the result of the applied
+   `bodyClosure` property.
+   */
+  let bodyType: Any.Type
+
   public init<V>(_ view: V) where V: View {
     if let anyView = view as? AnyView {
-      type = anyView.type
-      typeConstructorName = anyView.typeConstructorName
-      bodyType = anyView.bodyType
-      self.view = anyView.view
-      bodyClosure = anyView.bodyClosure
+      self = anyView
     } else {
       type = V.self
 

From bd6c7857a55ffe5deec9cb30a4ee2f917e3468d7 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 18:44:53 +0100
Subject: [PATCH 07/13] Fix environment propagation and reflection bugs

---
 .../TokamakCore/MountedViews/MountedApp.swift | 37 +++++++---------
 .../MountedCompositeElement.swift             | 11 ++---
 .../MountedViews/MountedCompositeView.swift   |  5 ++-
 .../MountedViews/MountedElement.swift         | 42 +++++++++----------
 .../MountedViews/MountedHostView.swift        | 11 +----
 .../MountedViews/MountedScene.swift           | 28 ++++++++-----
 Sources/TokamakCore/StackReconciler.swift     |  8 ++--
 Sources/TokamakDemo/main.swift                | 11 ++++-
 8 files changed, 75 insertions(+), 78 deletions(-)

diff --git a/Sources/TokamakCore/MountedViews/MountedApp.swift b/Sources/TokamakCore/MountedViews/MountedApp.swift
index b77d14056..3c8b7f96b 100644
--- a/Sources/TokamakCore/MountedViews/MountedApp.swift
+++ b/Sources/TokamakCore/MountedViews/MountedApp.swift
@@ -49,33 +49,28 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
       self,
       with: element,
       getElementType: { $0.type },
-      updateChild: { $0.scene = _AnyScene(element) },
+      updateChild: {
+        $0.environmentValues = environmentValues
+        $0.scene = _AnyScene(element)
+      },
       mountChild: { mountChild($0) }
     )
   }
 }
 
-extension App {
-  func makeMountedApp<R>(_ parentTarget: R.TargetType,
-                         _ environmentValues: EnvironmentValues)
-    -> MountedApp<R> where R: Renderer {
-    // Find Environment changes
-    var injectableApp = self
-    let any = (injectableApp as? _AnyApp) ?? _AnyApp(injectableApp)
-    // swiftlint:disable force_try
+extension _AnyApp {
+  func makeMountedApp<R>(
+    _ parentTarget: R.TargetType,
+    _ environmentValues: EnvironmentValues
+  ) -> MountedApp<R> where R: Renderer {
+    // swiftlint:disable:next force_try
+    let info = try! typeInfo(of: type)
 
-    let appInfo = try! typeInfo(of: any.type)
-    var extractedApp = any.app
+    var modified = app
+    info.injectEnvironment(from: environmentValues, into: &modified)
 
-    appInfo.injectEnvironment(from: environmentValues, into: &extractedApp)
-
-    // Set the extractedApp back on the AnyApp after modification
-    let anyAppInfo = try! typeInfo(of: _AnyApp.self)
-    try! anyAppInfo.property(named: "app").set(value: extractedApp, on: &injectableApp)
-    // swiftlint:enable force_try
-
-    // Make MountedView
-    let anyApp = injectableApp as? _AnyApp ?? _AnyApp(injectableApp)
-    return MountedApp(anyApp, parentTarget, environmentValues)
+    var result = self
+    result.app = modified
+    return MountedApp(result, parentTarget, environmentValues)
   }
 }
diff --git a/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift b/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
index 22d68f46f..05efc8958 100644
--- a/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
@@ -27,28 +27,23 @@ class MountedCompositeElement<R: Renderer>: MountedElement<R>, Hashable {
     hasher.combine(ObjectIdentifier(self))
   }
 
-  var mountedChildren = [MountedElement<R>]()
   let parentTarget: R.TargetType
 
   var state = [Any]()
   var subscriptions = [AnyCancellable]()
-  var environmentValues: EnvironmentValues
 
   init(_ app: _AnyApp, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
     self.parentTarget = parentTarget
-    self.environmentValues = environmentValues
-    super.init(app)
+    super.init(app, environmentValues)
   }
 
   init(_ scene: _AnyScene, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
     self.parentTarget = parentTarget
-    self.environmentValues = environmentValues
-    super.init(scene)
+    super.init(scene, environmentValues)
   }
 
   init(_ view: AnyView, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
     self.parentTarget = parentTarget
-    self.environmentValues = environmentValues
-    super.init(view)
+    super.init(view, environmentValues)
   }
 }
diff --git a/Sources/TokamakCore/MountedViews/MountedCompositeView.swift b/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
index d477097a1..db2de569d 100644
--- a/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
+++ b/Sources/TokamakCore/MountedViews/MountedCompositeView.swift
@@ -45,7 +45,10 @@ final class MountedCompositeView<R: Renderer>: MountedCompositeElement<R> {
       self,
       with: element,
       getElementType: { $0.type },
-      updateChild: { $0.view = AnyView(element) },
+      updateChild: {
+        $0.environmentValues = environmentValues
+        $0.view = AnyView(element)
+      },
       mountChild: { $0.makeMountedView(parentTarget, environmentValues) }
     )
   }
diff --git a/Sources/TokamakCore/MountedViews/MountedElement.swift b/Sources/TokamakCore/MountedViews/MountedElement.swift
index 8910af708..73313e569 100644
--- a/Sources/TokamakCore/MountedViews/MountedElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedElement.swift
@@ -85,16 +85,22 @@ public class MountedElement<R: Renderer> {
     }
   }
 
-  init(_ app: _AnyApp) {
+  var mountedChildren = [MountedElement<R>]()
+  var environmentValues: EnvironmentValues
+
+  init(_ app: _AnyApp, _ environmentValues: EnvironmentValues) {
     element = .app(app)
+    self.environmentValues = environmentValues
   }
 
-  init(_ scene: _AnyScene) {
+  init(_ scene: _AnyScene, _ environmentValues: EnvironmentValues) {
     element = .scene(scene)
+    self.environmentValues = environmentValues
   }
 
-  init(_ view: AnyView) {
+  init(_ view: AnyView, _ environmentValues: EnvironmentValues) {
     element = .view(view)
+    self.environmentValues = environmentValues
   }
 
   func mount(with reconciler: StackReconciler<R>) {
@@ -137,41 +143,31 @@ extension TypeInfo {
   }
 }
 
-extension View {
+extension AnyView {
   func makeMountedView<R: Renderer>(
     _ parentTarget: R.TargetType,
     _ environmentValues: EnvironmentValues
   ) -> MountedElement<R> {
     // Find Environment changes
     var modifiedEnv = environmentValues
-    var injectableView = self
-    let any = (injectableView as? AnyView) ?? AnyView(injectableView)
     // swiftlint:disable force_try
     // Extract the view from the AnyView for modification
-    var extractedView = any.view
-    let viewInfo = try! typeInfo(of: any.type)
-    if viewInfo
-      .genericTypes
-      .filter({ $0 is EnvironmentModifier.Type }).count > 0 {
+    let viewInfo = try! typeInfo(of: type)
+    if viewInfo.genericTypes.filter({ $0 is EnvironmentModifier.Type }).count > 0 {
       // Apply Environment changes:
-      if let modifier = try? viewInfo
+      if let modifier = try! viewInfo
         .property(named: "modifier")
-        .get(from: any.view) as? EnvironmentModifier {
+        .get(from: view) as? EnvironmentModifier {
         modifier.modifyEnvironment(&modifiedEnv)
       }
     }
+    var modifiedView = view
+    viewInfo.injectEnvironment(from: environmentValues, into: &modifiedView)
 
-    viewInfo.injectEnvironment(from: environmentValues, into: &extractedView)
-
-    // Set the extractedView back on the AnyView after modification
-    let anyViewInfo = try! typeInfo(of: AnyView.self)
-    try! anyViewInfo.property(named: "view").set(value: extractedView, on: &injectableView)
-    // swiftlint:enable force_try
-
-    // Make MountedView
-    let anyView = injectableView as? AnyView ?? AnyView(injectableView)
+    var anyView = self
+    anyView.view = modifiedView
     if anyView.type == EmptyView.self {
-      return MountedNull(anyView)
+      return MountedNull(anyView, modifiedEnv)
     } else if anyView.bodyType == Never.self && !(anyView.type is ViewDeferredToRenderer.Type) {
       return MountedHostView(anyView, parentTarget, modifiedEnv)
     } else {
diff --git a/Sources/TokamakCore/MountedViews/MountedHostView.swift b/Sources/TokamakCore/MountedViews/MountedHostView.swift
index 9ab89c29c..7c6e14e9b 100644
--- a/Sources/TokamakCore/MountedViews/MountedHostView.swift
+++ b/Sources/TokamakCore/MountedViews/MountedHostView.swift
@@ -21,8 +21,6 @@ import Runtime
  views by `StackReconciler`.
  */
 public final class MountedHostView<R: Renderer>: MountedElement<R> {
-  private var mountedChildren = [MountedElement<R>]()
-
   /** Target of a closest ancestor host view. As a parent of this view
    might not be a host view, but a composite view, we need to pass
    around the target of a host view to its closests descendant host
@@ -33,15 +31,10 @@ public final class MountedHostView<R: Renderer>: MountedElement<R> {
   /// Target of this host view supplied by a renderer after mounting has completed.
   private var target: R.TargetType?
 
-  private let environmentValues: EnvironmentValues
-
-  init(_ view: AnyView,
-       _ parentTarget: R.TargetType,
-       _ environmentValues: EnvironmentValues) {
+  init(_ view: AnyView, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
     self.parentTarget = parentTarget
-    self.environmentValues = environmentValues
 
-    super.init(view)
+    super.init(view, environmentValues)
   }
 
   override func mount(with reconciler: StackReconciler<R>) {
diff --git a/Sources/TokamakCore/MountedViews/MountedScene.swift b/Sources/TokamakCore/MountedViews/MountedScene.swift
index d91e93205..239a65a61 100644
--- a/Sources/TokamakCore/MountedViews/MountedScene.swift
+++ b/Sources/TokamakCore/MountedViews/MountedScene.swift
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+import Runtime
+
 final class MountedScene<R: Renderer>: MountedCompositeElement<R> {
   let title: String?
 
@@ -46,6 +48,7 @@ final class MountedScene<R: Renderer>: MountedCompositeElement<R> {
       with: element,
       getElementType: { $0.type },
       updateChild: {
+        $0.environmentValues = environmentValues
         switch element {
         case let .scene(scene):
           $0.scene = _AnyScene(scene)
@@ -86,23 +89,28 @@ extension _AnyScene {
     _ parentTarget: R.TargetType,
     _ environmentValues: EnvironmentValues
   ) -> MountedScene<R> {
+    // swiftlint:disable:next force_try
+    let info = try! typeInfo(of: type)
+
+    var modified = scene
+    info.injectEnvironment(from: environmentValues, into: &modified)
+
     var title: String?
-    if let titledSelf = scene as? TitledScene,
+    if let titledSelf = modified as? TitledScene,
       let text = titledSelf.title {
       title = _TextProxy(text).rawText
     }
     let children: [MountedElement<R>]
-    if let deferredSelf = scene as? SceneDeferredToRenderer {
-      children = [deferredSelf.deferredBody.makeMountedView(parentTarget, environmentValues)]
-    } else if let groupSelf = scene as? GroupScene {
-      children = groupSelf.children.map { $0.makeMountedScene(parentTarget, environmentValues) }
+    if let deferredScene = modified as? SceneDeferredToRenderer {
+      children = [deferredScene.deferredBody.makeMountedView(parentTarget, environmentValues)]
+    } else if let groupScene = modified as? GroupScene {
+      children = groupScene.children.map { $0.makeMountedScene(parentTarget, environmentValues) }
     } else {
-      fatalError("""
-      Unsupported `Scene` type `\(type)`. Please file a bug report at \
-      https://github.com/swiftwasm/Tokamak/issues/new
-      """)
+      children = []
     }
 
-    return .init(self, title, children, parentTarget, environmentValues)
+    var result = self
+    result.scene = modified
+    return .init(result, title, children, parentTarget, environmentValues)
   }
 }
diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index 0db5e7f67..cdd6b7a9d 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -74,7 +74,7 @@ public final class StackReconciler<R: Renderer> {
     self.scheduler = scheduler
     rootTarget = target
 
-    rootElement = view.makeMountedView(target, environment)
+    rootElement = AnyView(view).makeMountedView(target, environment)
 
     rootElement.mount(with: self)
   }
@@ -90,13 +90,13 @@ public final class StackReconciler<R: Renderer> {
     self.scheduler = scheduler
     rootTarget = target
 
-    rootElement = app.makeMountedApp(target, environment)
+    rootElement = _AnyApp(app).makeMountedApp(target, environment)
 
     rootElement.mount(with: self)
     if let mountedApp = rootElement as? MountedApp<R> {
       app._phasePublisher.sink { [weak self] phase in
-        if mountedApp.environmentValues[keyPath: \.scenePhase] != phase {
-          mountedApp.environmentValues[keyPath: \.scenePhase] = phase
+        if mountedApp.environmentValues.scenePhase != phase {
+          mountedApp.environmentValues.scenePhase = phase
           self?.queueUpdate(for: mountedApp)
         }
       }.store(in: &mountedApp.subscriptions)
diff --git a/Sources/TokamakDemo/main.swift b/Sources/TokamakDemo/main.swift
index db5930c17..c29cbe20e 100644
--- a/Sources/TokamakDemo/main.swift
+++ b/Sources/TokamakDemo/main.swift
@@ -15,17 +15,24 @@
 import TokamakShim
 
 @available(OSX 10.16, iOS 14.0, *)
-struct TokamakDemoApp: App {
+struct CustomScene: Scene {
   @Environment(\.scenePhase) private var scenePhase
 
   var body: some Scene {
-    print(scenePhase)
+    print("In CustomScene.body scenePhase is \(scenePhase)")
     return WindowGroup("Tokamak Demo") {
       TokamakDemoView()
     }
   }
 }
 
+@available(OSX 10.16, iOS 14.0, *)
+struct TokamakDemoApp: App {
+  var body: some Scene {
+    CustomScene()
+  }
+}
+
 // If @main was supported for executable Swift Packages,
 // this would match SwiftUI 100%
 if #available(OSX 10.16, iOS 14.0, *) {

From 201da0a4d1e9be616600fe2916ed5d8ac6e8a58b Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 18:48:48 +0100
Subject: [PATCH 08/13] Rename `MountedNull` to `MountedEmptyView`

---
 Sources/TokamakCore/MountedViews/MountedElement.swift           | 2 +-
 .../MountedViews/{MountedNull.swift => MountedEmptyView.swift}  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
 rename Sources/TokamakCore/MountedViews/{MountedNull.swift => MountedEmptyView.swift} (93%)

diff --git a/Sources/TokamakCore/MountedViews/MountedElement.swift b/Sources/TokamakCore/MountedViews/MountedElement.swift
index 73313e569..ebf43f939 100644
--- a/Sources/TokamakCore/MountedViews/MountedElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedElement.swift
@@ -167,7 +167,7 @@ extension AnyView {
     var anyView = self
     anyView.view = modifiedView
     if anyView.type == EmptyView.self {
-      return MountedNull(anyView, modifiedEnv)
+      return MountedEmptyView(anyView, modifiedEnv)
     } else if anyView.bodyType == Never.self && !(anyView.type is ViewDeferredToRenderer.Type) {
       return MountedHostView(anyView, parentTarget, modifiedEnv)
     } else {
diff --git a/Sources/TokamakCore/MountedViews/MountedNull.swift b/Sources/TokamakCore/MountedViews/MountedEmptyView.swift
similarity index 93%
rename from Sources/TokamakCore/MountedViews/MountedNull.swift
rename to Sources/TokamakCore/MountedViews/MountedEmptyView.swift
index acc358cf1..8cf96ecb8 100644
--- a/Sources/TokamakCore/MountedViews/MountedNull.swift
+++ b/Sources/TokamakCore/MountedViews/MountedEmptyView.swift
@@ -15,7 +15,7 @@
 //  Created by Max Desiatov on 05/01/2019.
 //
 
-final class MountedNull<R: Renderer>: MountedElement<R> {
+final class MountedEmptyView<R: Renderer>: MountedElement<R> {
   override func mount(with reconciler: StackReconciler<R>) {}
 
   override func unmount(with reconciler: StackReconciler<R>) {}

From 0517b1cd5b047c2e106fd0cbfc97af0a55ba1b12 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 18:50:21 +0100
Subject: [PATCH 09/13] Fix doc comments

---
 Sources/TokamakCore/StackReconciler.swift | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index cdd6b7a9d..4eb227b30 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -50,13 +50,13 @@ public final class StackReconciler<R: Renderer> {
    */
   private let rootElement: MountedElement<R>
 
-  /** A renderer instances to delegate to. Usually the renderer owns the reconciler instance, thus
+  /** A renderer instance to delegate to. Usually the renderer owns the reconciler instance, thus
    the reference has to be weak to avoid a reference cycle.
    **/
   private(set) weak var renderer: R?
 
-  /** A platform-specific implementation of an event loop cycle scheduler. Usually reconciler
-   updates are scheduled in reponse to user input. To make the updates non-blocking so that app
+  /** A platform-specific implementation of an event loop scheduler. Usually reconciler
+   updates are scheduled in reponse to user input. To make updates non-blocking so that the app
    feels responsive, the actual reconcilliation needs to be scheduled on the next event loop cycle.
    Usually it's `DispatchQueue.main.async` on platforms where `Dispatch` is supported, or
    `setTimeout` in the DOM environment.

From 5c556d4c2f728ba564a6a8f7aba1b7bf3cdca687 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 20:20:48 +0100
Subject: [PATCH 10/13] Refactor StackReconiler.render to use closures

---
 Sources/TokamakCore/StackReconciler.swift | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index 4eb227b30..8cc2e0a43 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -175,9 +175,11 @@ public final class StackReconciler<R: Renderer> {
     }.store(in: &compositeElement.subscriptions)
   }
 
-  func render<T>(compositeElement: MountedCompositeElement<R>,
-                 body bodyKeypath: ReferenceWritableKeyPath<MountedCompositeElement<R>, Any>,
-                 result: KeyPath<MountedCompositeElement<R>, (Any) -> T>) -> T {
+  func render<T>(
+    compositeElement: MountedCompositeElement<R>,
+    body bodyKeypath: ReferenceWritableKeyPath<MountedCompositeElement<R>, Any>,
+    bodyClosure: (MountedCompositeElement<R>) -> T
+  ) -> T {
     let info = try! typeInfo(of: compositeElement.elementType)
     info.injectEnvironment(from: compositeElement.environmentValues,
                            into: &compositeElement[keyPath: bodyKeypath])
@@ -198,19 +200,19 @@ public final class StackReconciler<R: Renderer> {
       }
     }
 
-    return compositeElement[keyPath: result](compositeElement[keyPath: bodyKeypath])
+    return bodyClosure(compositeElement)
   }
 
   func render(compositeView: MountedCompositeView<R>) -> AnyView {
-    render(compositeElement: compositeView, body: \.view.view, result: \.view.bodyClosure)
+    render(compositeElement: compositeView, body: \.view.view) { $0.view.bodyClosure($0.view.view) }
   }
 
   func render(mountedApp: MountedApp<R>) -> _AnyScene {
-    render(compositeElement: mountedApp, body: \.app.app, result: \.app.bodyClosure)
+    render(compositeElement: mountedApp, body: \.app.app) { $0.app.bodyClosure($0.app.app) }
   }
 
   func render(mountedScene: MountedScene<R>) -> _AnyScene.BodyResult {
-    render(compositeElement: mountedScene, body: \.scene.scene, result: \.scene.bodyClosure)
+    render(compositeElement: mountedScene, body: \.scene.scene) { $0.scene.bodyClosure($0.scene.scene) }
   }
 
   func reconcile<Element>(

From 3d60370cb12b12c40488a60881127eb4a845affd Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 20:58:10 +0100
Subject: [PATCH 11/13] Work in progress

---
 README.md                                     | 39 ++++------
 Sources/TokamakCore/DynamicProperty.swift     | 16 ++--
 .../TokamakCore/MountedViews/MountedApp.swift | 21 +++--
 .../MountedCompositeElement.swift             |  2 +-
 .../MountedViews/MountedElement.swift         | 28 ++++---
 .../MountedViews/MountedScene.swift           | 10 +--
 Sources/TokamakCore/Renderer.swift            | 14 ++--
 Sources/TokamakCore/StackReconciler.swift     | 78 ++++++++-----------
 Sources/TokamakCore/Target.swift              | 50 +-----------
 Sources/TokamakDOM/DOMNode.swift              |  9 +--
 Sources/TokamakDOM/DOMRenderer.swift          | 27 +------
 Sources/TokamakDOM/Views/HTML.swift           |  2 +-
 12 files changed, 107 insertions(+), 189 deletions(-)

diff --git a/README.md b/README.md
index 8eea2cd09..8b58c45dd 100644
--- a/README.md
+++ b/README.md
@@ -48,23 +48,18 @@ struct Counter: View {
     }
   }
 }
-```
-
-You can then render your view in any DOM node captured with
-[JavaScriptKit](https://github.com/kateinoigakukun/JavaScriptKit/), just
-pass it as an argument to the `DOMRenderer` initializer together with your view:
-
-```swift
-import JavaScriptKit
-import TokamakDOM
 
-let document = JSObjectRef.global.document.object!
-
-let divElement = document.createElement!("div").object!
-let renderer = DOMRenderer(Counter(count: 5, limit: 15), divElement)
+struct CounterApp: App {
+  var body: some Scene {
+    WindowGroup("Counter Demo") {
+      Counter(count: 5, limit: 15)
+    }
+  }
+}
 
-let body = document.body.object!
-_ = body.appendChild!(divElement)
+// @main attribute is not supported in SwiftPM apps.
+// See https://bugs.swift.org/browse/SR-12683 for more details.
+CounterApp.main()
 ```
 
 ### Arbitrary HTML
@@ -108,9 +103,9 @@ app.
 ## Requirements for app developers
 
 - macOS 10.15 and Xcode 11.4/11.5/11.6 for macOS. Xcode betas are currently not supported. You can have
-those installed, but please make sure you use 
-[`xcode-select`](https://developer.apple.com/library/archive/technotes/tn2339/_index.html#//apple_ref/doc/uid/DTS40014588-CH1-HOW_DO_I_SELECT_THE_DEFAULT_VERSION_OF_XCODE_TO_USE_FOR_MY_COMMAND_LINE_TOOLS_) 
-to point it to a release version of Xcode.
+  those installed, but please make sure you use
+  [`xcode-select`](https://developer.apple.com/library/archive/technotes/tn2339/_index.html#//apple_ref/doc/uid/DTS40014588-CH1-HOW_DO_I_SELECT_THE_DEFAULT_VERSION_OF_XCODE_TO_USE_FOR_MY_COMMAND_LINE_TOOLS_)
+  to point it to a release version of Xcode.
 - [Swift 5.2 or later](https://swift.org/download/) for Linux.
 
 ## Requirements for app users
@@ -128,7 +123,7 @@ Not all of these were tested though, compatibility reports are very welcome!
 
 Tokamak relies on [`carton`](https://carton.dev) as a primary build tool. As a part of these steps
 you'll install `carton` via [Homebrew](https://brew.sh/) on macOS (unfortunately you'll have to build
-it manually on Linux). Assuming you already have Homebrew installed, you can create a new Tokamak 
+it manually on Linux). Assuming you already have Homebrew installed, you can create a new Tokamak
 app by following these steps:
 
 1. Install `carton`:
@@ -156,15 +151,15 @@ carton init --template tokamak
 ```
 
 4. Build the project and start the development server, `carton dev` can be kept running
-during development:
+   during development:
 
 ```
 carton dev
 ```
 
 5. Open [http://127.0.0.1:8080/](http://127.0.0.1:8080/) in your browser to see the app
-running. You can edit the app source code in your favorite editor and save it, `carton` 
-will immediately rebuild the app and reload all browser tabs that have the app open.
+   running. You can edit the app source code in your favorite editor and save it, `carton`
+   will immediately rebuild the app and reload all browser tabs that have the app open.
 
 You can also clone this repository and run `carton dev` in its root directory. This
 will build the demo app that shows almost all of the currently implemented APIs.
diff --git a/Sources/TokamakCore/DynamicProperty.swift b/Sources/TokamakCore/DynamicProperty.swift
index 8735c2d8c..ae608c0b2 100644
--- a/Sources/TokamakCore/DynamicProperty.swift
+++ b/Sources/TokamakCore/DynamicProperty.swift
@@ -29,9 +29,11 @@ extension TypeInfo {
   /// Extract all `DynamicProperty` from a type, recursively.
   /// This is necessary as a `DynamicProperty` can be nested.
   /// `EnvironmentValues` can also be injected at this point.
-  func dynamicProperties(_ environment: EnvironmentValues,
-                         source: inout Any,
-                         shouldUpdate: Bool) -> [PropertyInfo] {
+  func dynamicProperties<T>(
+    _ environment: EnvironmentValues,
+    source: inout T,
+    shouldUpdate: Bool
+  ) -> [PropertyInfo] {
     var dynamicProps = [PropertyInfo]()
     for prop in properties where prop.type is DynamicProperty.Type {
       dynamicProps.append(prop)
@@ -40,9 +42,11 @@ extension TypeInfo {
       propInfo.injectEnvironment(from: environment, into: &source)
       var extracted = try! prop.get(from: source)
       dynamicProps.append(
-        contentsOf: propInfo.dynamicProperties(environment,
-                                               source: &extracted,
-                                               shouldUpdate: shouldUpdate)
+        contentsOf: propInfo.dynamicProperties(
+          environment,
+          source: &extracted,
+          shouldUpdate: shouldUpdate
+        )
       )
       // swiftlint:disable:next force_cast
       var extractedDynamicProp = extracted as! DynamicProperty
diff --git a/Sources/TokamakCore/MountedViews/MountedApp.swift b/Sources/TokamakCore/MountedViews/MountedApp.swift
index 3c8b7f96b..419551fc5 100644
--- a/Sources/TokamakCore/MountedViews/MountedApp.swift
+++ b/Sources/TokamakCore/MountedViews/MountedApp.swift
@@ -34,11 +34,10 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
     mountedChildren.forEach { $0.unmount(with: reconciler) }
   }
 
-  private func mountChild(_ childBody: _AnyScene) -> MountedElement<R> {
-    let mountedScene: MountedScene<R> = childBody.makeMountedScene(parentTarget, environmentValues)
+  private func mountChild<S: Scene>(_ scene: S) -> MountedElement<R> {
+    let mountedScene: MountedScene<R> = scene.makeMountedScene(parentTarget, environmentValues)
     if let title = mountedScene.title {
-      // swiftlint:disable force_cast
-      (app.type as! _TitledApp.Type)._setTitle(title)
+      R.AppType._setTitle(title)
     }
     return mountedScene
   }
@@ -48,7 +47,7 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
     reconciler.reconcile(
       self,
       with: element,
-      getElementType: { $0.type },
+      getElementType: { type(of: $0) },
       updateChild: {
         $0.environmentValues = environmentValues
         $0.scene = _AnyScene(element)
@@ -58,19 +57,17 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
   }
 }
 
-extension _AnyApp {
+extension App {
   func makeMountedApp<R>(
     _ parentTarget: R.TargetType,
     _ environmentValues: EnvironmentValues
-  ) -> MountedApp<R> where R: Renderer {
+  ) -> MountedApp<R> where R: Renderer, R.AppType == Self {
     // swiftlint:disable:next force_try
-    let info = try! typeInfo(of: type)
+    let info = try! typeInfo(of: Self.self)
 
-    var modified = app
+    var modified = self
     info.injectEnvironment(from: environmentValues, into: &modified)
 
-    var result = self
-    result.app = modified
-    return MountedApp(result, parentTarget, environmentValues)
+    return MountedApp(modified, parentTarget, environmentValues)
   }
 }
diff --git a/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift b/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
index 05efc8958..886b53ea5 100644
--- a/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedCompositeElement.swift
@@ -32,7 +32,7 @@ class MountedCompositeElement<R: Renderer>: MountedElement<R>, Hashable {
   var state = [Any]()
   var subscriptions = [AnyCancellable]()
 
-  init(_ app: _AnyApp, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
+  init(_ app: R.AppType, _ parentTarget: R.TargetType, _ environmentValues: EnvironmentValues) {
     self.parentTarget = parentTarget
     super.init(app, environmentValues)
   }
diff --git a/Sources/TokamakCore/MountedViews/MountedElement.swift b/Sources/TokamakCore/MountedViews/MountedElement.swift
index ebf43f939..2f9a929b3 100644
--- a/Sources/TokamakCore/MountedViews/MountedElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedElement.swift
@@ -17,17 +17,17 @@
 
 import Runtime
 
-/// The container for any of the possible `MountedElement` types
-enum MountedElementKind {
-  case app(_AnyApp)
-  case scene(_AnyScene)
-  case view(AnyView)
-}
-
 public class MountedElement<R: Renderer> {
-  private var element: MountedElementKind
+  /// The container for any of the possible "raw" element types
+  enum Kind {
+    case app(R.AppType)
+    case scene(_AnyScene)
+    case view(AnyView)
+  }
 
-  public internal(set) var app: _AnyApp {
+  private var element: Kind
+
+  public internal(set) var app: R.AppType {
     get {
       if case let .app(app) = element {
         return app
@@ -67,7 +67,11 @@ public class MountedElement<R: Renderer> {
 
   var elementType: Any.Type {
     switch element {
-    case let .app(app): return app.type
+    case .app: fatalError("""
+    `App` values aren't supposed to be reconciled, thus the type constructor name is not stored \
+    for `App` elements. Please report this crash as a bug at \
+    https://github.com/swiftwasm/Tokamak/issues/new
+    """)
     case let .scene(scene): return scene.type
     case let .view(view): return view.type
     }
@@ -88,7 +92,7 @@ public class MountedElement<R: Renderer> {
   var mountedChildren = [MountedElement<R>]()
   var environmentValues: EnvironmentValues
 
-  init(_ app: _AnyApp, _ environmentValues: EnvironmentValues) {
+  init(_ app: R.AppType, _ environmentValues: EnvironmentValues) {
     element = .app(app)
     self.environmentValues = environmentValues
   }
@@ -117,7 +121,7 @@ public class MountedElement<R: Renderer> {
 }
 
 extension TypeInfo {
-  func injectEnvironment(from environmentValues: EnvironmentValues, into element: inout Any) {
+  func injectEnvironment<E>(from environmentValues: EnvironmentValues, into element: inout E) {
     // Inject @Environment values
     // swiftlint:disable force_cast
     // swiftlint:disable force_try
diff --git a/Sources/TokamakCore/MountedViews/MountedScene.swift b/Sources/TokamakCore/MountedViews/MountedScene.swift
index 239a65a61..b937deafa 100644
--- a/Sources/TokamakCore/MountedViews/MountedScene.swift
+++ b/Sources/TokamakCore/MountedViews/MountedScene.swift
@@ -84,15 +84,15 @@ extension _AnyScene.BodyResult {
   }
 }
 
-extension _AnyScene {
+extension Scene {
   func makeMountedScene<R: Renderer>(
     _ parentTarget: R.TargetType,
     _ environmentValues: EnvironmentValues
   ) -> MountedScene<R> {
     // swiftlint:disable:next force_try
-    let info = try! typeInfo(of: type)
+    let info = try! typeInfo(of: Self.self)
 
-    var modified = scene
+    var modified = self
     info.injectEnvironment(from: environmentValues, into: &modified)
 
     var title: String?
@@ -109,8 +109,6 @@ extension _AnyScene {
       children = []
     }
 
-    var result = self
-    result.scene = modified
-    return .init(result, title, children, parentTarget, environmentValues)
+    return .init(_AnyScene(modified), title, children, parentTarget, environmentValues)
   }
 }
diff --git a/Sources/TokamakCore/Renderer.swift b/Sources/TokamakCore/Renderer.swift
index 2f49cbae5..1923d645f 100644
--- a/Sources/TokamakCore/Renderer.swift
+++ b/Sources/TokamakCore/Renderer.swift
@@ -25,11 +25,13 @@ public protocol Renderer: AnyObject {
   typealias Mounted = MountedElement<Self>
   typealias MountedHost = MountedHostView<Self>
 
+  associatedtype AppType: App
+
   /** Views are rendered to platform-specific targets with a renderer.
    Usually a target is a simple view (`UIView` and `NSView` for `UIKit`
    and `AppKit` respectively).
    */
-  associatedtype TargetType: Target
+  associatedtype TargetType
 
   /// Reconciler instance used by this renderer.
   var reconciler: StackReconciler<Self>? { get }
@@ -41,20 +43,14 @@ public protocol Renderer: AnyObject {
    - parameter view: The host view that renders to the newly created target.
    - returns: The newly created target.
    */
-  func mountTarget(
-    to parent: TargetType,
-    with host: MountedHost
-  ) -> TargetType?
+  func mountTarget(to parent: TargetType, with host: MountedHost) -> TargetType?
 
   /** Function called by a reconciler when an existing target instance should be
    updated.
    - parameter target: Existing target instance to be updated.
    - parameter view: The host view that renders to the updated target.
    */
-  func update(
-    target: TargetType,
-    with host: MountedHost
-  )
+  func update(target: TargetType, with host: MountedHost)
 
   /** Function called by a reconciler when an existing target instance should be
    unmounted: removed from the parent and most likely destroyed.
diff --git a/Sources/TokamakCore/StackReconciler.swift b/Sources/TokamakCore/StackReconciler.swift
index 8cc2e0a43..c881448f7 100644
--- a/Sources/TokamakCore/StackReconciler.swift
+++ b/Sources/TokamakCore/StackReconciler.swift
@@ -48,7 +48,7 @@ public final class StackReconciler<R: Renderer> {
 
   /** A root of the mounted elements tree to which all other mounted elements are attached to.
    */
-  private let rootElement: MountedElement<R>
+  private let mountedApp: MountedApp<R>
 
   /** A renderer instance to delegate to. Usually the renderer owns the reconciler instance, thus
    the reference has to be weak to avoid a reference cycle.
@@ -63,8 +63,8 @@ public final class StackReconciler<R: Renderer> {
    */
   private let scheduler: (@escaping () -> ()) -> ()
 
-  public init<V: View>(
-    view: V,
+  public init(
+    app: R.AppType,
     target: R.TargetType,
     environment: EnvironmentValues,
     renderer: R,
@@ -74,33 +74,15 @@ public final class StackReconciler<R: Renderer> {
     self.scheduler = scheduler
     rootTarget = target
 
-    rootElement = AnyView(view).makeMountedView(target, environment)
+    mountedApp = app.makeMountedApp(target, environment)
 
-    rootElement.mount(with: self)
-  }
-
-  public init<A: App>(
-    app: A,
-    target: R.TargetType,
-    environment: EnvironmentValues,
-    renderer: R,
-    scheduler: @escaping (@escaping () -> ()) -> ()
-  ) {
-    self.renderer = renderer
-    self.scheduler = scheduler
-    rootTarget = target
-
-    rootElement = _AnyApp(app).makeMountedApp(target, environment)
-
-    rootElement.mount(with: self)
-    if let mountedApp = rootElement as? MountedApp<R> {
-      app._phasePublisher.sink { [weak self] phase in
-        if mountedApp.environmentValues.scenePhase != phase {
-          mountedApp.environmentValues.scenePhase = phase
-          self?.queueUpdate(for: mountedApp)
-        }
-      }.store(in: &mountedApp.subscriptions)
-    }
+    mountedApp.mount(with: self)
+    app._phasePublisher.sink { [weak self, weak mountedApp] phase in
+      if let mountedApp = mountedApp, mountedApp.environmentValues.scenePhase != phase {
+        mountedApp.environmentValues.scenePhase = phase
+        self?.queueUpdate(for: mountedApp)
+      }
+    }.store(in: &mountedApp.subscriptions)
   }
 
   private func queueStateUpdate(
@@ -129,11 +111,11 @@ public final class StackReconciler<R: Renderer> {
     queuedRerenders.removeAll()
   }
 
-  private func setupState(
+  private func setupState<Element>(
     id: Int,
     for property: PropertyInfo,
     of compositeElement: MountedCompositeElement<R>,
-    body bodyKeypath: ReferenceWritableKeyPath<MountedCompositeElement<R>, Any>
+    body bodyKeypath: ReferenceWritableKeyPath<MountedCompositeElement<R>, Element>
   ) {
     // swiftlint:disable force_try
     // `ValueStorage` property already filtered out, so safe to assume the value's type
@@ -158,10 +140,10 @@ public final class StackReconciler<R: Renderer> {
     try! property.set(value: state, on: &compositeElement[keyPath: bodyKeypath])
   }
 
-  private func setupSubscription(
+  private func setupSubscription<Element>(
     for property: PropertyInfo,
     of compositeElement: MountedCompositeElement<R>,
-    body bodyKeypath: KeyPath<MountedCompositeElement<R>, Any>
+    body bodyKeypath: KeyPath<MountedCompositeElement<R>, Element>
   ) {
     // `ObservedProperty` property already filtered out, so safe to assume the value's type
     // swiftlint:disable force_cast
@@ -175,11 +157,11 @@ public final class StackReconciler<R: Renderer> {
     }.store(in: &compositeElement.subscriptions)
   }
 
-  func render<T>(
+  func render<Element, Body>(
     compositeElement: MountedCompositeElement<R>,
-    body bodyKeypath: ReferenceWritableKeyPath<MountedCompositeElement<R>, Any>,
-    bodyClosure: (MountedCompositeElement<R>) -> T
-  ) -> T {
+    body bodyKeypath: ReferenceWritableKeyPath<MountedCompositeElement<R>, Element>,
+    bodyClosure: (MountedCompositeElement<R>) -> Body
+  ) -> Body {
     let info = try! typeInfo(of: compositeElement.elementType)
     info.injectEnvironment(from: compositeElement.environmentValues,
                            into: &compositeElement[keyPath: bodyKeypath])
@@ -187,9 +169,11 @@ public final class StackReconciler<R: Renderer> {
     let needsSubscriptions = compositeElement.subscriptions.isEmpty
 
     var stateIdx = 0
-    let dynamicProps = info.dynamicProperties(compositeElement.environmentValues,
-                                              source: &compositeElement[keyPath: bodyKeypath],
-                                              shouldUpdate: true)
+    let dynamicProps = info.dynamicProperties(
+      compositeElement.environmentValues,
+      source: &compositeElement[keyPath: bodyKeypath],
+      shouldUpdate: true
+    )
     for property in dynamicProps {
       // Setup state/subscriptions
       if property.type is ValueStorage.Type {
@@ -204,15 +188,21 @@ public final class StackReconciler<R: Renderer> {
   }
 
   func render(compositeView: MountedCompositeView<R>) -> AnyView {
-    render(compositeElement: compositeView, body: \.view.view) { $0.view.bodyClosure($0.view.view) }
+    render(compositeElement: compositeView, body: \.view.view) {
+      $0.view.bodyClosure($0.view.view)
+    }
   }
 
-  func render(mountedApp: MountedApp<R>) -> _AnyScene {
-    render(compositeElement: mountedApp, body: \.app.app) { $0.app.bodyClosure($0.app.app) }
+  func render(mountedApp: MountedApp<R>) -> some Scene {
+    render(compositeElement: mountedApp, body: \.app) {
+      $0.app.body
+    }
   }
 
   func render(mountedScene: MountedScene<R>) -> _AnyScene.BodyResult {
-    render(compositeElement: mountedScene, body: \.scene.scene) { $0.scene.bodyClosure($0.scene.scene) }
+    render(compositeElement: mountedScene, body: \.scene.scene) {
+      $0.scene.bodyClosure($0.scene.scene)
+    }
   }
 
   func reconcile<Element>(
diff --git a/Sources/TokamakCore/Target.swift b/Sources/TokamakCore/Target.swift
index f7cd9f4bc..d96a484f5 100644
--- a/Sources/TokamakCore/Target.swift
+++ b/Sources/TokamakCore/Target.swift
@@ -15,52 +15,6 @@
 //  Created by Max Desiatov on 10/02/2019.
 //
 
-open class Target {
-  var element: MountedElementKind
-  public internal(set) var app: _AnyApp {
-    get {
-      if case let .app(app) = element {
-        return app
-      } else {
-        fatalError("`Target` has type \(element) not `App`")
-      }
-    }
-    set {
-      element = .app(newValue)
-    }
-  }
-
-  public internal(set) var scene: _AnyScene {
-    get {
-      if case let .scene(scene) = element {
-        return scene
-      } else {
-        fatalError("`Target` has type \(element) not `Scene`")
-      }
-    }
-    set {
-      element = .scene(newValue)
-    }
-  }
-
-  public internal(set) var view: AnyView {
-    get {
-      if case let .view(view) = element {
-        return view
-      } else {
-        fatalError("`Target` has type \(element) not `View`")
-      }
-    }
-    set {
-      element = .view(newValue)
-    }
-  }
-
-  public init<V: View>(_ view: V) {
-    element = .view(AnyView(view))
-  }
-
-  public init<A: App>(_ app: A) {
-    element = .app(_AnyApp(app))
-  }
+protocol Target {
+  var view: AnyView { get set }
 }
diff --git a/Sources/TokamakDOM/DOMNode.swift b/Sources/TokamakDOM/DOMNode.swift
index 46761b58e..a9d44dafe 100644
--- a/Sources/TokamakDOM/DOMNode.swift
+++ b/Sources/TokamakDOM/DOMNode.swift
@@ -18,19 +18,18 @@ import TokamakCore
 public final class DOMNode: Target {
   let ref: JSObjectRef
   private var listeners: [String: JSClosure]
+  private let view: AnyView?
 
   init<V: View>(_ view: V, _ ref: JSObjectRef, _ listeners: [String: Listener] = [:]) {
     self.ref = ref
     self.listeners = [:]
-    super.init(view)
+    self.view = AnyView(view)
     reinstall(listeners)
   }
 
-  init<A: App>(_ app: A, _ ref: JSObjectRef, _ listeners: [String: Listener] = [:]) {
+  init(_ ref: JSObjectRef) {
     self.ref = ref
-    self.listeners = [:]
-    super.init(app)
-    reinstall(listeners)
+    listeners = [:]
   }
 
   /// Removes all existing event listeners on this DOM node and install new ones from
diff --git a/Sources/TokamakDOM/DOMRenderer.swift b/Sources/TokamakDOM/DOMRenderer.swift
index e9f5ffe9c..890898d4d 100644
--- a/Sources/TokamakDOM/DOMRenderer.swift
+++ b/Sources/TokamakDOM/DOMRenderer.swift
@@ -72,33 +72,14 @@ func appendRootStyle(_ rootNode: JSObjectRef) {
   _ = head.appendChild!(rootStyle)
 }
 
-public final class DOMRenderer: Renderer {
+public final class DOMRenderer<A: App>: Renderer {
+  public typealias AppType = A
+
   public private(set) var reconciler: StackReconciler<DOMRenderer>?
 
   private let rootRef: JSObjectRef
 
-  public init<V: View>(
-    _ view: V,
-    _ ref: JSObjectRef,
-    _ rootEnvironment: EnvironmentValues? = nil
-  ) {
-    rootRef = ref
-    appendRootStyle(ref)
-
-    reconciler = StackReconciler(
-      view: view,
-      target: DOMNode(view, ref),
-      environment: .defaultEnvironment,
-      renderer: self,
-      scheduler: timeoutScheduler
-    )
-  }
-
-  init<A: App>(
-    _ app: A,
-    _ ref: JSObjectRef,
-    _ rootEnvironment: EnvironmentValues? = nil
-  ) {
+  init(_ app: A, _ ref: JSObjectRef, _ rootEnvironment: EnvironmentValues? = nil) {
     rootRef = ref
     appendRootStyle(ref)
 
diff --git a/Sources/TokamakDOM/Views/HTML.swift b/Sources/TokamakDOM/Views/HTML.swift
index 366cea43d..9685055b4 100644
--- a/Sources/TokamakDOM/Views/HTML.swift
+++ b/Sources/TokamakDOM/Views/HTML.swift
@@ -37,7 +37,7 @@ extension AnyHTML {
     """
   }
 
-  func update(dom: DOMNode) {
+  func update<A: App>(dom: DOMNode<A>) {
     // FIXME: is there a sensible way to diff attributes and listeners to avoid
     // crossing the JavaScript bridge and touching DOM if not needed?
 

From f8026eeb5f2a17e66947ceeace1555eff1d58a39 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Wed, 29 Jul 2020 21:12:16 +0100
Subject: [PATCH 12/13] Fully remove _AnyApp

---
 Sources/TokamakCore/App/_AnyApp.swift         | 54 -------------------
 .../MountedViews/MountedElement.swift         |  6 +--
 Sources/TokamakCore/Renderer.swift            |  2 +-
 Sources/TokamakCore/Target.swift              |  2 +-
 Sources/TokamakDOM/DOMNode.swift              |  3 +-
 Sources/TokamakDOM/DOMRenderer.swift          |  2 +-
 Sources/TokamakDOM/Views/HTML.swift           |  2 +-
 7 files changed, 7 insertions(+), 64 deletions(-)
 delete mode 100644 Sources/TokamakCore/App/_AnyApp.swift

diff --git a/Sources/TokamakCore/App/_AnyApp.swift b/Sources/TokamakCore/App/_AnyApp.swift
deleted file mode 100644
index 24dc7a66a..000000000
--- a/Sources/TokamakCore/App/_AnyApp.swift
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2020 Tokamak contributors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-//  Created by Carson Katri on 7/19/20.
-//
-
-import OpenCombine
-
-public struct _AnyApp: App {
-  var app: Any
-  let type: Any.Type
-  let bodyClosure: (Any) -> _AnyScene
-  let bodyType: Any.Type
-
-  init<A: App>(_ app: A) {
-    self.app = app
-    type = A.self
-    // swiftlint:disable:next force_cast
-    bodyClosure = { _AnyScene(($0 as! A).body) }
-    bodyType = A.Body.self
-  }
-
-  public var body: Never {
-    neverScene("_AnyApp")
-  }
-
-  public init() {
-    fatalError("`_AnyApp` cannot be initialized without an underlying `App` type.")
-  }
-
-  public static func _launch(_ app: Self,
-                             _ rootEnvironment: EnvironmentValues) {
-    fatalError("`_AnyApp` cannot be launched. Access underlying `app` value.")
-  }
-
-  public static func _setTitle(_ title: String) {
-    fatalError("`title` cannot be set for `AnyApp`. Access underlying `app` value.")
-  }
-
-  public var _phasePublisher: CurrentValueSubject<ScenePhase, Never> {
-    fatalError("`_AnyApp` cannot monitor scenePhase. Access underlying `app` value.")
-  }
-}
diff --git a/Sources/TokamakCore/MountedViews/MountedElement.swift b/Sources/TokamakCore/MountedViews/MountedElement.swift
index 2f9a929b3..8713f88e8 100644
--- a/Sources/TokamakCore/MountedViews/MountedElement.swift
+++ b/Sources/TokamakCore/MountedViews/MountedElement.swift
@@ -67,11 +67,7 @@ public class MountedElement<R: Renderer> {
 
   var elementType: Any.Type {
     switch element {
-    case .app: fatalError("""
-    `App` values aren't supposed to be reconciled, thus the type constructor name is not stored \
-    for `App` elements. Please report this crash as a bug at \
-    https://github.com/swiftwasm/Tokamak/issues/new
-    """)
+    case .app: return R.AppType.self
     case let .scene(scene): return scene.type
     case let .view(view): return view.type
     }
diff --git a/Sources/TokamakCore/Renderer.swift b/Sources/TokamakCore/Renderer.swift
index 1923d645f..c64a0aa4f 100644
--- a/Sources/TokamakCore/Renderer.swift
+++ b/Sources/TokamakCore/Renderer.swift
@@ -31,7 +31,7 @@ public protocol Renderer: AnyObject {
    Usually a target is a simple view (`UIView` and `NSView` for `UIKit`
    and `AppKit` respectively).
    */
-  associatedtype TargetType
+  associatedtype TargetType: Target
 
   /// Reconciler instance used by this renderer.
   var reconciler: StackReconciler<Self>? { get }
diff --git a/Sources/TokamakCore/Target.swift b/Sources/TokamakCore/Target.swift
index d96a484f5..fcd683a70 100644
--- a/Sources/TokamakCore/Target.swift
+++ b/Sources/TokamakCore/Target.swift
@@ -15,6 +15,6 @@
 //  Created by Max Desiatov on 10/02/2019.
 //
 
-protocol Target {
+public protocol Target: AnyObject {
   var view: AnyView { get set }
 }
diff --git a/Sources/TokamakDOM/DOMNode.swift b/Sources/TokamakDOM/DOMNode.swift
index a9d44dafe..99c2bd03c 100644
--- a/Sources/TokamakDOM/DOMNode.swift
+++ b/Sources/TokamakDOM/DOMNode.swift
@@ -18,7 +18,7 @@ import TokamakCore
 public final class DOMNode: Target {
   let ref: JSObjectRef
   private var listeners: [String: JSClosure]
-  private let view: AnyView?
+  public var view: AnyView
 
   init<V: View>(_ view: V, _ ref: JSObjectRef, _ listeners: [String: Listener] = [:]) {
     self.ref = ref
@@ -29,6 +29,7 @@ public final class DOMNode: Target {
 
   init(_ ref: JSObjectRef) {
     self.ref = ref
+    view = AnyView(EmptyView())
     listeners = [:]
   }
 
diff --git a/Sources/TokamakDOM/DOMRenderer.swift b/Sources/TokamakDOM/DOMRenderer.swift
index 890898d4d..a3fcf9581 100644
--- a/Sources/TokamakDOM/DOMRenderer.swift
+++ b/Sources/TokamakDOM/DOMRenderer.swift
@@ -85,7 +85,7 @@ public final class DOMRenderer<A: App>: Renderer {
 
     reconciler = StackReconciler(
       app: app,
-      target: DOMNode(app, ref),
+      target: DOMNode(ref),
       environment: .defaultEnvironment,
       renderer: self,
       scheduler: timeoutScheduler
diff --git a/Sources/TokamakDOM/Views/HTML.swift b/Sources/TokamakDOM/Views/HTML.swift
index 9685055b4..366cea43d 100644
--- a/Sources/TokamakDOM/Views/HTML.swift
+++ b/Sources/TokamakDOM/Views/HTML.swift
@@ -37,7 +37,7 @@ extension AnyHTML {
     """
   }
 
-  func update<A: App>(dom: DOMNode<A>) {
+  func update(dom: DOMNode) {
     // FIXME: is there a sensible way to diff attributes and listeners to avoid
     // crossing the JavaScript bridge and touching DOM if not needed?
 

From 7ca57349a0995c5c0e52cb282b4f0970e922f3c8 Mon Sep 17 00:00:00 2001
From: Max Desiatov <max@desiatov.com>
Date: Mon, 28 Sep 2020 18:30:08 +0100
Subject: [PATCH 13/13] Update
 Sources/TokamakCore/MountedViews/MountedApp.swift

Co-authored-by: Jed Fox <git@jedfox.com>
---
 Sources/TokamakCore/MountedViews/MountedApp.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/TokamakCore/MountedViews/MountedApp.swift b/Sources/TokamakCore/MountedViews/MountedApp.swift
index 419551fc5..c479a8390 100644
--- a/Sources/TokamakCore/MountedViews/MountedApp.swift
+++ b/Sources/TokamakCore/MountedViews/MountedApp.swift
@@ -47,7 +47,7 @@ final class MountedApp<R: Renderer>: MountedCompositeElement<R> {
     reconciler.reconcile(
       self,
       with: element,
-      getElementType: { type(of: $0) },
+      getElementType: type(of:),
       updateChild: {
         $0.environmentValues = environmentValues
         $0.scene = _AnyScene(element)